We have found that cGMP-dependent protein kinase (G-kinase) regulates transcription of the c-fos gene apparently through three different response elements, i.e., a CRE, TRE and SRE. One previous publication indicates that G-kinase translocates to the nucleus in human monocytes but this was not rigorously established. G-kinase does have a nuclear translocation sequence and we have evidence in G-kinase transfected cells by immunofluorescent microscopy that G-kinase does translocate to the nucleus when the cells are treated with a membrane-permeable cGMP analog. Using confocal microscopy on cells stained with a highly specific polyclonal G-kinase antibody we have obtained evidence that G-kinase is actually in the nucleus rather than around the nuclear envelope. In addition, we have now tagged our protein with the green fluorescent protein and there is preliminary evidence that the protein becomes intranuclear. This work was submitted for publication.